I know 10 would be enough for when the game becomes more populated, but as an addition to the inventory increase, i believe it would be in best interest to increase the bazaar slot limit to 50 or more.

The reason why i say this is to create a motive for crafters to make items for low level players and help them out. This would really speed up the process of finding that sweet spot of what price to set for which items.

I'd certainly love to sell my armor and help new players than to sell to a vendor. I am hoping that I can have more than 10 slots for each retainer at least, im not asking for 50 slots on the main character.

This is how I see it..

Main Character (100 Inventory/ 10 Bazaar)
Retainer (200 Inventory/ 50 Bazaar)

It just makes more sense to me that way. I honestly think that the bazaar slots should be unlimited, but I'm not sure what would become of the game economy if that were to happen. I think 50 is a good number for now though.